A generator is an electrical machine that converts mechanical energy into electrical energy, producing either an alternating current or a direct current. There are two types of DC generators in present technology. One type of DC generator is a rotating magnet generator with a rectifier. The rotating magnet generator is generally known as an alternator that generates AC power and then is rectified into DC power. The other type of DC generator is a rotating coil generator that produces AC current and is used with a commutator to make the current unidirectional. In both types of generators, the induced current through the coil is alternating current. The relative motion of a rotating coil in a steady magnetic field or stationary coil in a rotating magnetic field will produce an induced electromotive force, also known as emf or voltage, and an associated current. Since, generally, the current produced is alternating, the rectifier or commutator is necessary to change the alternating current to direct current. However, there are many applications in which the traditional design of such DC generators is too large and inefficient. One of these applications is recharging batteries used in portable computers, cellular phones, automobiles, motorcycles or other devices, where it is required to recharge a battery efficiently.
A similar type of machine is an acyclic homopolar generator, which is a direct-current generator in which the poles presented to the armature are all of the same polarity, so that the voltage generated in active conductors has the same polarity at all times. Thus, a direct current is produced, without commutation. However, due to the single conductor design of most homopolar generators, it can only produce low voltages, so it is generally only useful in low voltage applications.
U.S. Pat. No. 5,278,470 to Neag discloses a homopolar machine for producing high voltage, direct current. The machine is comprised of a stator which supports the homopolar machine, a plurality of excitation coils disposed within the stator for producing magnetic flux so that the homopolar machines can produce direct current when in operation, a rotor rotationally disposed within the excitation coils for rotating through the magnetic flux when the homopolar machine is in operation to produce direct current, and a coil of a single length continuous conductor element disposed about the rotor such that a plurality of rotor conductor segments are formed wherein successive ones of the plurality of conductor segments are electrically connected such that an induced voltage and direct current are produced in the coil when the rotor and coil traverse through the magnetic flux during homopolar machine operation.
It is an object of the present invention to provide a generator that generates true DC power in the coil without the need for commutation or rectification. It is another object to provide a generator that is efficient and does not incur the usual eddy current or hysteresis losses which occur in almost all rotating machines. It is still another object of the present invention to provide a generator that is useful for recharging batteries and a motor which may be driven by such batteries.